Dynamo.



PATENTED SEPT. 13, 1904.

M. G. BURT. DYNAMO.

APPLIUATION FILED NOV. 14, 1903.

2 SHEETSSHEET 1.

NO MODEL.

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' M. G. BURT DYNAMO.

APPLIOATION FILED NOV. 14, 1903.

2 SHEETS-SHEET 2.

N0 MODEL.

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PATENT OFFICE.

MARTIN C. BURT, OF CHICAGO, ILLINOIS.

DYNAMO.

SPECIFICATION forming part of Letters Patent No. 769,815, dated September 13, 1904. Application filed November 14, 1903. Serial No. 181,182 (No model.)

To (tZZ whom it may concern:

Be it known that I, MARTIN C. BURT, a citi- Zen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dynamos, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to improvements in electric machines, and more particularly to motors or dynamos, and has for its primary object the provision of an armature possessing many desirable characteristics tending to further the beneficial results sought to be attained by the structure constituting the subject-matter of my prior Patent No. 463,242, issued November 17, 1891.

With the foregoing object in view the invention comprehends an armature having a hollow interior and means therewithin for effecting a circulation therethrough.

The invention further com prehends a drumarmature provided with the usual exterior wiring inclosing an interior structure consisting of aseries of laminated or separated plates or sheets arranged in parallel planes and suitably insulated apart.

The plates are preferably, though not essentially, bellied or formed with concavo-convex central portions, whereby the nesting of the said plates is facilitated and their heat-absorbing capacity materially increased.

In the preferred embodiment of the invention the bellied portions gradually increase in diameter from the inlet end of the armature to the outlet end of the same, communication between the respective plates being afforded by suitable apertures. A circulation of air through the armature is induced by the formation and arrangement of the plates in a manner to be hereinafter explained, and said circulation may be augmented through the medium of a suction-fan arranged within the cup or hollow portion ofone of the plates.

Another important feature of the invention resides in the means for insuring the passage of at least a portion of the cooling medium through the wiring on the exterior of the armature, to attain which result the total capacity of the inlet-openings of the armature is somewhat less than the total capacity of the exit-openings thereof, said inlet and exit openings being arranged at opposite ends of the armature, whereby, owing to the limited discharge at the exit end of the armature, as the air is forced into the interior of the armature a pressure is created therein which causes the air to take a radial course outward through the wiring.

All of the above, as well as many other novel details of the present invention, will be apparent from the detailed description hereinafter when read in connection with the accompanying drawings, forming part hereof, wherein several convenient embodiments of the invention are illustrated. It is to be understood, however, that in any future interpretation as to the scope of the present invention the same is in no sense to be limited to the precise construction or arrangement specified herein, excepting in so far as such may bedefined in the hereto-appended claims.

In the drawings, Figure l is a perspective view of a dynamo made in accordance with my present improvements. Fig. 2 is a longitudinal sectional View of the drum-armature, parts being shown in elevation. Fig. 3 is a similar view, some of the parts being omitted, of a slightly-modified construction; and Fig. 4 is a transverse sectional view on the line :1; m of Fig. 2 looking in the direction of the arrows.

Referring more specifically to the drawings, wherein like reference characters refer to corresponding parts in the several views, A designates a supporting-base, and B B supporting standards or brackets projecting upwardly therefrom, the upper ends of said brackets being formed into alined bearings b for the reception of the armature-shaft C, carrying at its protruding end an operating-pulley D. Upon the base and intermediate the brackets B B the field-coils E are supported, the same having the usual cores 6, secured to which are the pole-pieces F, the inner opposing facesof which are substantially semicircular to provide a suitable space for an armature G. This armature is of the peculiar formation to be now described. I

- H represents the usual longitudinal wiring of a drum-armature forming the inclosing casing or covering thereof. On the interior of the armature within the space or chamber inclosed by the wiring referred to I provide a series of laminated or closely-associated sheets or plates I, the same being slightly separated through the medium of insulating instrumentalities. Each plate is bellied or formed with a dished or concavo-convex central portion '5, whereby the heat-absorbing capacity of the plates is materially increased. This formation of the plates also facilitates the nesting thereof, as clearly seen in Fig. 2. The shaft C passes through suitable apertures in the plates and is insulated therefrom and the several plates from each other by a sectional flanged bushing J encircling said shaft, and the plates are further insulated through the medium of a plurality of abutting thimbles J through which passes securing-rods j, cooperating With suitable binding-nuts j, impinging upon the outermost plates of the series. The bellied portions of the plates are each provided with a multiplicity of perforations t, which afford communication between the several spaces between the plates and also therethrough from the inlet to the outlet ends of the armature.

K K represent cap-plates fitting the ends of the armature, the former being arranged at the inlet end thereof and the latter at the outlet end of the same. The cap-plate K is provided with a plurality of air passages k, through which air is afforded access to the interior of the armature from the exterior of the machine, while the cap-plate K has several similar openings k through which said air escapes from the interior of the machine to the exterior thereof, the differentiating characteristic of these two series of openings being that the total inlet capacity of the one greatly exceeds the total outlet capacity of the other. The purpose of this is that whether the current of air through the armature be induced or forced, as hereinafter explained, by reason of the restricted outlet therefor at the exit end of the machine relative to the intake of the air a slight compression of air will take place on theinterior of the armature, resulting in a forced escape of part of the air radially of the armature and between the wires H, which is a very desirable feature in that it I preserves the insulation of the wiring ordithe same through the apertures in the plates into the spaces therebetween and out between the wires H and the escape-openings 7c in the cap-plate K. This circulation is augmented by the gradual increasing of the diameters of the bellied portions of the plates from the inlet to the outlet ends of the armature, and by reason of this special arrangement and formation of said plates the use of the suction-fan may in some cases be dispensed with. When the fan is not used, the circulation through the armature is induced in keeping with the theory that the air on the interior of the armature becoming heated will rise to the highest point therein, which will necessarily be at the exit end thereof, owing to the increased size of the bellied portions of the plates, and this rising of the heated air at the exit end of the armature will create to a greater or less degree the suction at the air-intake end of the armature. In this manner a sufiicient circulation for the more ordinary purposes is effected.

In the modified embodiment (shown in Fig. 3) the bellied portions of the plates are all of the same size, a fan for producing a forced circulation being shown at I].

It is obvious that many changes and alterations may be made in the several structures and arrangements referred to herein without in the least departing from the spirit of the invention.

Having thus described the invention, what vis claimed as new, and desired to be secured by Letters Patent, is

1. In combination with an armature having a hollow interior, a series of plates, one of said plates having a hollow portion and a fan arranged within said hollow portion of said plate for effecting a circulation therethrough.

2. In combination with an armature having a hollow interior, a series of plates having perforated bellied portions located withinthe armature, the diameters of said bellied portions increasing toward the exit end of the armature.

3. In combination with an armature having a hollow interior, a series of plates having hollow central portions located Within the armature, the diameters of said hollow portions increasing toward the exit end of the armature.

4. In combination with an armature having a hollow interior, a series of plates having communicating openings located within the armature, said openings being arranged nearer the periphery of the disks at the exit end of the armature than at the inlet end thereof.

5. In combination with an armature having a hollow interior, a series of plates having perforated bellied portions located within the armature, and a fan in the bellied portion of one of the plates for effecting a circulation therethrough.

6. In combination with an armature having a hollow interior, a series of plates having perforated bellied portions located within the armature, said plates being nested and separated to provide spaces therebetween, and a fan in the bellied portion of one of the plates for effecting a circulation therethrough.

7. In combination with an armature having a hollow interior, a series of plates one of which has a bellied portion located within the armature, and a fan in said bellied portion for eifecting a circulation therethrough.

8. In combination with an armature having a hollow interior, a plate therewithin having a bellied portion, and a fan in said bellied portion for effecting a circulation therethrough.

9. In combination with an armature having a hollow interior and inlet and outlet ends, the capacity of the outlet being restricted relative to the capacity of the inlet, and means within the armature for efl ecting a circulation therethrough longitudinally and radially thereof.

10. In combination with an armature having a hollow interior and inlet and outlet ends, the capacity of the outlet being restricted relative to the capacity of the inlet, and a fan within the armature for effecting a circulation therethrough longitudinally and radially thereof.

11. In combination with an armature having a hollow interior and inlet and outlet ends, a series of nested plates within the armature, the capacity of the outlet being restricted relative to the capacity of the inlet whereby a circulation is effected between the plates and radially of the armature.

12. In combination with an armature having a hollow interior and inlet and outlet ends, caps on said ends provided with openings, the capacity of the openings in the cap at the inlet end of the armature being greater than the capacity of the openings at the outlet end thereof whereby a circulation radially of the armature is effected.

13. In combination with an armature having a hollow interior and inlet and outlet ends,

means forforcing air into the inlet end thereof, the capacity of the inlet being somewhat greater than the capacity of the outlet whereby a circulation radially of the armature is effected.

14. An armature having a hollow interior and inlet and outlet ends, the capacity of the outlet being restricted relative to the capacity of the inlet whereby a circulation radially of the armature is effected. 1

15. In combination with an armature having a hollow interior, a series of plates having perforated bellied portions located within the armature, the diameters of said bellied portions increasing toward the exit end of the armature, and a fan arranged in the bellied portion of one of the plates.

16. In combination with an armature having a hollow interior, a series of plates having communicating openings therein located within the'armature, said openings being arranged nearer the periphery of the disks at the exit end of the armature than at the inlet end thereof, and a fan also located within the armature.

17. In combination with an armature having a hollow interior and inlet and outlet ends, a series of plates within the armature, the capacity of the outlet being restricted relative to the capacity of the inlet whereby a circulation is effected between the plates and radially of the armature. 18. In combination with an armature having a hollow interior and inlet and outlet ends, a series of plates having perforated bellied portions within the armature, the capacity of the outlet being restricted relative to the capacity of the inlet whereby a circulation is effected between the plates and radially of the armature.

In testimony whereof I aflix my signature in presence of two witnesses.

MARTIN O. BURT. IVitnesses:

HAROLD E. STONEBRAKER, J. PERCY CAMPBELL. 

